Why Good Improvement Projects Stall: Change-Management Mistakes in Lean Six Sigma
Most Lean Six Sigma projects do not fail on the numbers. The control charts are clean, the root cause is real, the new process genuinely runs faster. They fail because the people who have to live with the change were never brought along. In a year like this one, with staff stretched thin by labour shortages, materials arriving late, and half the team still finding its rhythm after a return to the office, the human side of improvement is where projects quietly die.
The discipline of Lean Six Sigma is built around DMAIC: Define, Measure, Analyze, Improve, Control. The tools tell you how to find and fix a problem. They say much less about how to get a frustrated, busy, slightly suspicious group of people to actually adopt the fix. That gap is where most of the avoidable mistakes live.
The mistakes that quietly sink projects
Treating the project as a side hobby. If a belt is expected to run an improvement project on top of a full day job, with no protected time and no executive sponsor, the message to everyone else is that this work is optional. People mirror what leadership funds, not what it announces.
Skipping the case for change. Teams often jump straight to the solution because the data feels obvious. But the people on the floor do not see your data; they see one more thing being done to them. Without a plain answer to "why now, and what happens if we do nothing," you get compliance at best and quiet sabotage at worst.
Designing the fix in a conference room. An improvement built without the operators who run the process every day will miss the workarounds, the exceptions, and the unwritten rules. Worse, those operators have no ownership of it, so the first time it is inconvenient, they revert.
Underestimating the Control phase. DMAIC ends in Control for a reason. Many teams celebrate at Improve, declare victory, and walk away. Six months later the gains have evaporated because nobody owned the new standard, the audit, or the response plan when the process drifts.
Ignoring the load on people. Asking a short-staffed team to absorb a new procedure during a volatile, high-pressure stretch, without removing anything from their plate, is a recipe for change fatigue. The improvement competes with survival, and survival wins.
How to step around them
Name a sponsor with real authority before Define, and make them visibly accountable for the outcome, not just the kickoff.
Build a one-page case for change in plain language: the problem, the cost of doing nothing, and what good looks like.
Involve the people who do the work from the Measure phase onward, not as a courtesy at the end but as co-authors of the fix.
Treat Control as a deliverable in its own right: a named process owner, a simple monitoring measure, and a documented reaction plan.
Stage the rollout so the team is not asked to change everything during the busiest, most fragile weeks.
None of this is soft. Change management is the part of improvement work that determines whether your hard analysis ever turns into a result that holds. Get the people side right and a modest technical fix will outperform a brilliant one that nobody adopted.
If you are running improvement work where the analysis is sound but the change keeps slipping, XNM's strategic advisory can help you build the sponsorship, sequencing, and ownership that make the gains stick.